高效液相色谱法测定水环境中壬基酚聚氧乙烯醚及其生物降解产物

应用固相萃取－高效液相色谱法调查了嘉陵江和长江重庆段的壬基酚聚氧乙烯醚(ＮＰｎＥＯ,ｎ＞３)的污染状况．在四月份,长江的Ａ,Ｂ和Ｃ,嘉陵江的Ｄ和Ｅ采样点都测定出了ＮＰｎＥＯ(ｎ＞３)．长江上游Ａ点的浓度最高,为３７．２８μｇ·ｌ－１,嘉陵江的下游Ｄ点的总浓度最低,为７．２１μｇ·ｌ－１．七月的水样中仅在Ａ,Ｄ,Ｅ点检测出ＮＰｎＥＯ(ｎ≥３),其总浓度最高为１．９９μｇ·ｌ－１．但其分解产物ＮＰ的浓度比四月份高．     

预浓缩-GC-MS技术研究室内空气中挥发性有毒有机物

研究了广州市８种典型室内环境中６２种挥发性有毒有机物(ＶＯＣｓ)的特征和分布,结果表明:(１)从低至高,家庭、歌舞厅、宾馆、餐厅、图书馆、办公室、大型商业城和停车库室内空气中总挥发性有毒有机物(ＴＶＯＣｓ)平均浓度分别为:０．２４１,０．２７１,０．４７１,０．４７６,０．５５６,０．９１０,１．１７７和２．１９０ｍｇ·ｍ－３;刑室外环境背景参照点白云山平均浓度为０．２１３ｍｇ·ｍ－３,略低于家庭;(２)室内空气污染物具有明显的源特征,根据其ＶＯＣｓ标志化合物和它们的混合比例可以初步判断其来源．     

Influence of the presence of heavy metals and surface-active compounds on the sorption of bisphenol A to sediment

The effects of different heavy metals (Cd, Pb), cationic surfactants cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecylbenzenesulfonate (SDBS) and the chemistry of the solution (pH and ionic strength) on the sorption of bisphenol A (BPA) to sediment were studied. Results showed that the presence of Cd and Pb caused a significant increase on the sorption of BPA to sediment and the sorption isotherms were in good agreement with Freundlich equation. The effect of surfactants on the adsorption of BPA onto sediment was found to strongly depend on the type of the surfactants. The presence of CTAB promoted BPA sorption and the amount of BPA adsorbed onto sediment increased linearly with concentration of CTAB. In contrast, the presence of anionic surfactant (SDBS) caused a slight reduction on the sorption of BPA. It was also found that the sorption behavior of BPA was affected by solution pH and ionic strength. The larger amount of BPA was absorbed with higher ionic strength and lower pH. This study may provide important insights into the understanding of the transport and fate of BPA in the environment.     

Application of an enzyme-linked immunosorbent assay for the detection of clenbuterol residues in swine urine and feeds

The present study outlines applications of an enzyme-linked immunosorbent assay (ELISA) for the analysis of clenbuterol residues. Antisera were raised from rabbits immunized with diazotized clenbuterol-bovine serum albumin (BSA) conjugate. The assay was specific to clenbuterol with a half-maximum inhibition concentration (IC(50)) of 1.8 ng/mL and 2.5 ng/mL in blank swine urine and phosphate buffer solution, respectively. The assay had high cross-reactivity (86%) with mabuterol, but low with other adrenergic agonists and antagonists. The average recovery of clenbuterol, as measured with the ELISA, ranged from 90% to 112% in swine urine samples and from 86% to 95% in feeds, respectively. This new assay was compared with commercial ELISA test kits. An excellent correlation (r(2) = 0.98) between the two methods and satisfactory recoveries suggest that the new assay can be suitable for the determination of clenbuterol residues in real samples. The assay was used to analyze clenbuterol residues in 103 swine urine samples and 68 feed samples collected from northern China. Approximately 50% of the urine samples and 25% of the feed samples analyzed were found positive (concentration of clenbuterol > or = 1 ppb). The results indicate that clenbuterol was misused in some of the areas surveyed.     

Chemical Elements and their Source Apportionment of PM10 in Beijing Urban Atmosphere

Ecological health in a temperate stream impacted by acid mine drainage (AMD) was evaluated by using a multimetric approach of the Index of Biological Integrity (IBI) based on natural fish assemblage. Recently, this approach has been widely used in many developed countries as a tool for ecological risk assessments of water environments. We used 10 metric systems, instead of 12 metrics suggested by Barbour, M. T., Gerritsen, J., Snyder, B. D., & Stribling, J. B. (1999). Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, benthic Macroinvertebrates and Fish, 2nd edn. EPA 841-B-99-002. Washington, DC: U.S. Environmental Protection Agency, Office of Water, for a development of the regional IBI model, and used trophic guilds, habitat guilds, and richness variables for the calculation of IBI values. In the model, the attributes of four of 11 metrics were modified for the regional application. IBI values in the stream averaged 20.6 (n = 5), indicating a “poor condition” in terms of ecological health according to the modified criteria of U.S. EPA (1993). Fish Field and Laboratory Methods for Evaluating the Biological Integrity of Surface Waters. EPA 600-R-92-111. Environmental Monitoring systems Laboratory – Cincinnati office of Modeling, Monitoring systems, and quality assurance Office of Research Development, U.S. EPA, Cincinnati, Ohio, 45268. In particular, mean IBI values in the impacted areas of sites 2 and 3 were 13, and this health condition was categorized as “very poor condition.” IBI values in the impacted sites were significantly lower than the values found in the control. Also, we found that fishes in site sites 2 and 3 were not present during the study, and morphological deformity of Rhynchocypris oxycephalus was observed in site 4, influenced directly by sites 2 and 3, indicating a chemical impact in the sites. From the results of experiments in which AMD was treated with marine shells at stagnant condition, pH increased up to 6.0 from 3.1, and Fe and Al were removed up to 99% within 6 h. In the reactor experiment considering field application, pH of effluent maintained around 7.0. In addition, concentrations of Fe, Al, and heavy metals decreased remarkably in the effluents, and bottom-opened screen between neutralizer basins showed high effectiveness in the treatment of AMD.     

Preliminary study on the occurrence and distribution of polycyclic musks in a wastewater treatment plant in Guandong, China

The occurrence and distributions of six polycyclic musks were studied in influent, primary and effluent waters from a municipal wastewater treatment plant (WWTP) in Guangdong. Five polycyclic musk compounds, 1,2,3,5,6,7-hexahydro-1,1,2,3,3-pentamethyl-4H-inden-4-one (DPMI), 4-acetyl-1,1-dimethyl-6-tert-butylindan (ADBI), 6-acetyl-1,1,2,3,3,5-hexamethylindan (AHMI), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) were found in wastewater in the WWTP. DPMI, HHCB and AHTN were measured at 0.38-0.69, 11.5-146, 0.89-3.47 microg/l, respectively, in influents. Meanwhile 0.06-0.10 microg/l DPMI, 0.95-2.05 microg/l HHCB, 0.10-0.14 microg/l AHTN were detected in effluents, ADBI and AHMI were also detected in some primary waters and effluents. The results suggested that wastewater from cosmetic plants cause high loadings of polycyclic musks to this WWTP. Under the currently applied treatment technology, the removal efficiencies achieved were 61-75% for DPMI, 86-97% for HHCB and 87-96% for AHTN by transfer to sludge as the main removal route.     

Methane emissions from ricefields as affected by organic amendment, water regime, crop establishment, and rice cultivar

Methane fluxes from Beijing ricefields as affected by organic amendment, water regime, crop establishment method, and rice cultivar were measured with a closed chamber method in 1990, 1991, 1995, and 1996. Total fluxes from plots receiving high organic amendment always exceeded those from the low-input plots. Compared with continuous flooding, intermittent irrigation (there were a few days of no standing water between two irrigations) and constant moisture (the field had no standing water, but remained saturated) reduced methane emission rate by 25.4 and 58.4%, respectively. Methane flux from a dry-seeded rice field was 75.2% lower than from a transplanted ricefield although both dry-seeded rice plots and transplanted ricefields were initially flooded at the same time. Rice cultivars differed in methane emission rates by 9.0–55.7%. Emission rates were positively correlated with aboveground dry matter production and root weight, but not grain yield. Intermittent irrigation and rice cultivar seem to be the most promising methods for mitigating methane emission from ricefields; they do not affect rice yield and are easily implemented at the farm level.     

Coexistence of antibiotic resistance genes,fecal bacteria,and potential pathogens in anthropogenically impacted water

Environmental Science and Pollution Research - Microbial indicators are often used to monitor microbial safety of aquatic environments. However, information regarding the correlation between...     

Macromolecule simulation studies on mechanical properties and CH4/CO2 adsorption characteristics in bituminous coal matrix based on uniaxial tension–compression effect

With the increasing complication of production and geology conditions, and the increase of mining intensity and depth in coal mine, the coal structure presents varying degrees of deformation. In order to study the influence of uniaxial tension–compression effect on mechanical properties of coal matrix and CH₄/CO₂ adsorption characteristics, a macromolecular model reflecting the realistic bituminous coal structure was established. Results demonstrate that the influence of tension strain on the microporous structural parameters is greater than that of compression strain, and the tension strain weakens the mechanical properties but enhances the adsorbates adsorption amount. For the pure gases adsorption, there is a negative linear correlation between the total energy and adsorption amount. Additionally, the strain ranging from??0.20 to 0.20, the distribution of punctated adsorbates density develops to that of banded adsorbates density, and the mean adsorption density and saturated adsorption amount increase linearly. For the binary components adsorption (1:1), the CH₄ adsorption strength increases while the CO₂ adsorption strength slightly decreases. The minimum of total energy decreases in a quadratic polynomial relationship with the strain, and the proportion of van der Waals energy is 75.8–85.5%. Nevertheless, the competitive adsorption and strain have little effect on the potential energy range of the adsorbates. Furthermore, the diffusibility of CO₂ molecular layers is relatively good, and the strain enhances the stability of CH₄ molecular layers for the saturated binary adsorption. The findings provide essential guidance for the improvement of carbon capture and storage and CO₂-enhanced coalbed methane technologies in the deformation area of coal seam.

     

Effects of Ginkgo biloba extract on growth,photosynthesis, and photosynthesis-related gene expression in Microcystis flos-aquae

Environmental Science and Pollution Research - The inhibitory effect of plants on algae offers a new and promising alternative method for controlling harmful algal blooms. Previous studies showed...